"We heard one of the civilians calling for help screaming, 'no, no, no, one of the kids is gonna die if they don't get here quick,'" recalled Will. "It almost felt like it was legitimately in our building. That's how loud it was."

"He was trying to do the good thing and a stray bullet took him," said Suazo's friend Patrick Martin. "He really tried to do what he had to do in life and God took him too soon."

The second victim, a 15-year-old boy, was taken to Tufts Medical Center with non-life-threatening injuries, according to authorities.